?Human health impacts that have been associated with these Lyngbya majuscula blooms include severe contact dermatitis causing affected skin to blister and peel off, eye irritation and asthma-like respiratory distress. The asthma-like respiratory symptoms have been reported by fisherman working with crab pots or ropes with dried L. majuscula, which forms a fine, easily aerosolised powder. There have been additional reports of similar symptoms from fisherman in contact with blooms off the coast of Bundaberg and Harvey Bay, as well as from swimmers and tourists off the oceanic beaches of Fraser Island. Extracts from L. majuscula in Moreton Bay have elicited rapid and strong responses using mouse ear swelling tests. Histological examination of mice injected with extracts of the cyanobacteria showed slight vacuolation at the surface of their kidneys.

Observed ecological health impacts of Lyngbya majuscula blooms in SE Queensland include: i) localised seagrass loss, ii) poor crab and fish harvests (reported by fishermen) compared with non-Lyngbya years, iii) localised input of bioavailable nitrogen through L. majuscula nitrogen fixation, iv) large beach wracks of decaying L. majuscula emitting a putrid odour necessitating the removal of the decomposing material by local authorities in the Deception Bay region. We hypothesise that Lyngbya blooms may be related to localised alterations of the micronutrient iron (Fe), as well as interaction with phosphorus (P).